LLC-type series resonant converter (LLC SRC) can be provided with characteristics that switches on the primary side can be zero-voltage switched and synchronous rectifier components on the secondary side can be zero-current switched. When the switch operation frequency of the converter is between the first resonant point and the second resonant point, zero-switching condition for the converter is independent of the load, and thus the characteristics that the zero-voltage switching (ZVS) for switches on the primary side and the zero-current switching (ZCS) for rectifier components on the secondary side can be achieved in a full range from lightly loaded to full loaded.
For a high wattage and low voltage output LLC series resonant converter architecture, the copper loss of the output winding and the loss of the magnetic component are one of the main sources of loss, and the overall volume is determined by the size of the magnetic component.
Therefore, how the above defects can be overcome to improve the copper loss of the output winding and the loss of the magnetic component through the improvement of the circuit and structure design has become an important issue in the art.